英语说明文概要写作中段落主题句的定位、提炼与转述

吉晨春

摘    要：主題句在英语说明文概要写作中的作用十分重要。主题句是段落主旨所在，综合各段主题句可知全文大意。英语说明文概要写作可以借助说明文的篇章结构特点与段落展开方式，定位与提炼主题句，从词、句、语法以及释义的角度转述主题句，从而个性化地表达主旨。

关键词：说明文;概要写作;段落主题句;定位;提炼

概要写作要求学生用自己的语言精准、连贯地写出所读文章的主旨大意。作为高考英语概要写作常用文体之一的英语说明文有开门见山的特点，即在起始段或导言部分揭示文章主题或阐述要说明的对象，随后的正文部分往往从不同的侧面、角度对说明对象进行具体说明，结尾段一般对说明对象再进行总的概括性说明。导言部分是主题所在。

说明文段落常由主题句和发展句或扩展句构成。主题句用来概括需要说明的事物、事理的特征，表达主题内容;发展句用来具体阐述事因、由来、利弊、功能、用途等。主题句与发展句的关系是上下关系，是概述与细说的关系，是结论与支撑的关系，它们相互依存[1]。当然，有的段落可能没有主题句，需要读者加以提炼。

主题句是段落主旨所在，综合各段主题句便可知说明文全文大意。由此可见，准确定位和提炼主题句是说明文概要写作的前提或保证，而用自己的语言个性化地转述主题句、表达主旨，则是说明文概要写作的关键。

一、主题句的定位与提炼

英语说明文段落的展开方式有多种。根据高中生英语学习的基础和认知水平，本文主要讨论在以特定顺序和以不同句式开头的两种段落展开方式下如何定位和提炼主题句。

（一）段落以特定顺序展开说明

1.逻辑顺序

逻辑顺序是说明文段落最主要的展开方式，即按照事物或事理的内部联系形成人们认识事物的过程来说明[2]。一般分为四种：演绎法（从一般到具体）、归纳法（从具体到一般）、归纳—演绎法（从具体到一般再到具体）和演绎—归纳法（从一般到具体再到一般）。

（1）演绎法

段落以从一般到具体的形式展开。作者在开头表明段落的中心思想，而后进行阐释论证，分点说明，最后得出结论，回应主题思想。这时，主题句在段首，后面的句子是扩展句。

例1   Written Chinese has also become an important means by which Chinas present is connected with its past. People in modern times can read the classic works which were written by Chinese in ancient times. The high regard for the Chinese writing system can be seen in the development of Chinese characters as an art form， known as Chinese calligraphy， which has become an important part of Chinese culture.

【解析】主题句在段首，后面扩展句围绕主题句分两个层次展开具体说明。

（2）归纳法

段落采用由具体向一般或概括发展的模式，即表述具体细节的句子在前，概述总结性的句子在后。这时，主题句置于段尾，前面的句子为扩展句。

例2   Rescue workers are trained to find people. Treat injuries， and hand out food， water， and other supplies. They have to be able to do work that is difficult under conditions which can be very dangerous. After a disaster， there is usually no electricity or water， and there may be diseases and accidents. Rescue workers get to save lives， but they must also bury the dead. That means they have to be strong in both body and mind.

【解析】本段前部分文字说明救援队员的工作内容以及所遇到的危险、疾病、事故等状况。最后一句将前面讲到的具体细节进行提炼概括：救援队员在身体和精神两方面的素质都得过硬。显然，最后一句是主题句，前面的句子都是扩展句，为后面的主题句作铺垫。

（3）归纳—演绎法

段落以“归纳—演绎”的形式展开，开头以有关细节或证据的句子为主题铺垫，随后归纳提炼出主题思想或观点，接着再用演绎法补充句子对主题加以论证。这时，主题句在段落中间。

例3   Everyone has heard of accountants， salespeople， and lawyers. But have you ever heard of a kiss mixer or a belly builder？ Most jobs have common titles， but there are also many unusual position titles. A kiss mixer， for instance， is the person who mixes the ingredients for candy kisses. And a belly builder is the individual who assembles and fits the inside parts of pianos.

【解析】首句介绍common titles for jobs，第二句提出有关a kiss mixer和a belly builder的问题。两句是为unusual position titles作铺垫。第三句but表明句子重心在此，为主题句。随后的句子进一步阐释a kiss mixer和a belly builder两个专业名词的内涵，符合“归纳—演绎”的段落展开模式。

当主题句在段中时，前面的句子有时不是为主题句作归纳铺垫，而是作为对照，但其作用仍然是引出所需重点说明的话题或内容。

例4   The four countries that belong to the United Kingdom work together in some areas. They use the same flag， known as the Union Jack， as well as share the same currency and military defence. However， they also have some differences. For example， England， Wales， Scotland and Northern Ireland all have their different education systems and legal systems. They also have their own traditions， like their own national days and national dishes. And they even have their own football teams for competitions like the World Cup！

【解析】前兩句讲的是英属四个区域的共同点，为下文重点需要说明的不同点作对照。第三句However引出本段着重要说明的差异性。从第四句开始往后的句子都是具体说明四个区域的差异所在。这样看来，第三句就是主题句。

（4）演绎—归纳法

英语说明文有时会出现段首和段尾都有与主题相关的句子。这时，作者先用演绎法展开段落，段首提出主题思想，中间句子做具体说明，段尾再用归纳法重申主题。这样，段落以“演绎—归纳”的方式展开，主题句在段首、尾，以首句为主。

例5   In the same way， many ordinary jobs may look plain， but they are necessary to society. As we go through our daily lives， we meet many different kinds of people—shopkeepers， who sell us things in shops; drivers， who drive trams and buses transporting us around the city; barbers， who cut our hair in barbershops， and cleaners， who clear up our rubbish. These jobs may not seem very attractive， but they are all important. For example， if no one was to collect the rubbish， the streets would soon become very dirty， the number of rats would increase， and disease would spread. These people， who perform such ordinary but vital tasks allow others to go about their daily lives.

【解析】段首In the same way承接上文，首句中画线部分是主题句，揭示本段重点要阐明的主题思想。随后的几句列举shopkeepers、drivers、barbers、cleaners等工作看起来似乎不那么有吸引力，但很重要。最后一句既是本段的总结，也是回应首句的主题思想，并作进一步重申和提高。

2.时间和空间顺序

时间顺序即按照事物发生、发展先后顺序来说明;空间顺序按照事物存在的空间形式或变化路径来说明，如从外到内、从上至下、由远而近等。英语说明文段落不一定按照一种顺序展开，有时呈现出以某种顺序为主的特点。

例6   Another unique human characteristic is that we walk upright. Standing up， its easier to find food or enemies. In addition， their arms that are unnecessary for moving around are freed for other purposes， like throwing stones or signaling. As a result， humans can perform very complex tasks with their hands.

【解析】此段以In addition，As a result短语为标记，以时间（或程序）顺序说明人直立行走过程中手臂逐步得到解放并为他用;从逻辑顺序来看，本段是以演绎法展开，首句概说主题思想，即人类的另一个特点是直立行走。后面都为扩展句，进一步说明人直立行走以后解放了双手用于其他目的。因此，主题句在段首。

当说明文说明的是一件事情或现象的发生、发展过程，段落更多地依据时间、空间顺序直叙其程序或步骤。有时，看起来都是具体的细节，但主题隐藏其中，只是没有现成的概括性主题句，这就需要学生学会捕捉与主题有关的词汇，提炼主题句。

例7   China opera developed from folk songs， dance， talking， antimasque and especially distinctive dialectical music. Gradually it combined music， art and literature into one performance on the stage. Accompanied by traditional musical instruments， actors present unique melodies which may sound strange to foreigners as well as beautifully written dialogues， which are of high literary value. These dialogues also promoted the development of distinct literary styles， such as Zaju in the Yuan Dynasty. For Chinese， especially older folks， listening to this kind of opera occasionally is a real pleasure.

【解析】此段以Gradually为时间顺序标记词，辅之以动词developed和promoted，依次说明京剧的起源、舞台表演艺术的产生、独特的文学价值和风格以及最终成为中国民众喜欢的一种艺术形式。此段没有明显的主题句。学生可以抓住与China opera有关的主题词汇，如developed、combined、music、art、literature，提炼主题句为：Developed from and combined with different arts， China opera is of great value in music， art and literature and popular with Chinese.

（二）段落以不同的句式开头展开说明

1.段首是疑问句

如果段首是疑问句，将问题和答案融合起来就可以提炼主题句。如果问题答案的后面出现but、however等转折词，那么，其后面的句子是重点，也常常是主题句所在。

例8   Does face-down generation need a heads-up？ Well， probably not. The fact is that many of todays teenagers are better educated and more creative than past generations. They also seem to be enthusiastic and willing to become leaders. More young generations than ever volunteer to help their communities. There are also brave young people such as Malala Yousafzai， the teenager who won the 2014 Nobel Peace Prize for pushing girls rights to go to school.

【解析】本段以一般疑問句开头提出主题，后一句的答案是否定的。分析段落展开方式可知，从第三句往后的句子是扩展句，为段首问题得到否定答案提供依据或佐证。由此，将问题和答案结合起来可提炼主题句：Face-down generation may not need a heads-up.

例9   Do you like to take selfies？ Its easy to take a quick picture of yourself to show what youre doing， or how youre feeling. But paying attention to ourselves often makes us feel worse. Therefore， try taking pictures of your friends. Do your best to highlight the wonderful things that make them special. In this way， you wont focus so much on your bad hair day， and you will get along better with your friends.

【解析】此段也以一般疑问句开头，但问句后没有直接给出答案，而是说明此问题意义不大。与例8有所不同，其后虽有but表示转折，但作者并没有在but后面的句子中表述主题思想，而是揭示了不理想的状况。而Therefore后面try taking pictures of your friends才是作者真正要提出的建议。再看接下去的句子讲的是给朋友拍照的好处，是对此句的扩展与延伸。因此，主题句应为段中的try taking pictures of your friends。

2.段首是陈述句

如果段首句是陈述句，必须分析其是否有扩展下文的空间和余地。比如，“Exercising is beneficial”就具有主题句概括性的特征，作者可以接着阐述或列举锻炼的好处，如锻炼可以增强体质、使人形象更美等。与之相对照，“The bird has a neck”就是一个有具体意义的句子，不容易再进一步扩展，做主题句的可能性小。

例10   Lighting matters， too. When Berlin restaurant customers ate in darkness， they couldnt tell how much theyd had： those given extra-large shares ate more than everyone else， none the wiser—they didnt feel fuller， and they were just as ready for dessert.

【解析】本段以演绎法展开，以陈述句“Lighting matters”开头，有主题句的特征，提出本段主题：灯光重要。后面句子都是在主题句之下进行的拓展，阐述了顾客在暗淡灯光下没有意识到吃得很多，被给了大份额食品的顾客吃得比别人多，还不觉得饱，继续要甜点。

3.段首是祈使句

如果段首是祈使句，该句常是主题句。这在介绍用途、注意事项、建议之类的说明文中尤其多见。

例11   Be sociable. Participating in clubs， activities， and sports increases your chances of meeting new friends. While you only need 4 or 5 close friends， that doesnt mean you shouldnt try to meet new people. Participating gives you something to do instead of sitting bored at home and wallowing in self-pity.

【解析】这段文字以祈使句开头作为主题句，第二句往后的句子是扩展句，进一步阐释Be sociable可以怎么做以及这么做的理由。

二、主题句的转述

一般来说，转述常有以下三种方法：从词或短语的角度入手，采用同义替换或词性转换的方法;从语法的角度转换主被动语态;从释义（paraphrase）的角度，对主题句进行重组和改写。

以例1至例5中的主题句为例。

Topic sentence 1  Written Chinese has also become an important means by which Chinas present is connected with its past.（句中also是对上文意义的增补，表示递进关系，在概要写作中可根据上下文需要选择保留或省略，在此单句中暂且忽略）

转述1   Written Chinese has become a significant way of connecting Chinas present and its past.（同义替换：an important means→ a significant way+语态转换：is connected→connecting）

转述2   Written Chinese has become a connection between Chinas present and its past.（词性转换：connected→connection+语态转换：an important means by which Chinas present is connected with its past→ a connection between Chinas present and its past）

转述3   Chinas present is linked to its past through the channel of written Chinese.（释义）

Topic sentence 2  They have to be strong in both body and mind.（They指上文Rescue workers。在脱离上下文的情况下，主题句中使用原名词替换代词意思更清楚）

转述1   Rescue workers must have a strong body and mind.（同义替换：have to be strong in both body and mind→ must have a strong body and mind）

轉述2   Rescue workers have to be strong both physically and spiritually.（词性转换：have a strong body and mind→be strong both physically and spiritually）

转述3   Rescue workers have to be well-built both physically and spiritually.（释义）

Topic sentence 3  There are also many unusual position titles.（在无上文的情况下此主题句看起来有点突兀。可以把原文中作为对照的Most jobs have common titles部分信息补充到主题句中，使其完整清晰）

转述1   Similarly， unusual jobs have their equivalent titles.（释义）

转述2   Like common jobs， there are lots of titles for unusual ones.（释义）

Topic sentence 4  They also have some differences.（用The four countries替换代词They，使主题句意思更为清楚）

转述1   There are some differences between the four countries. （同义替换：have→There are）

转述2   The four countries are different from one another.（词性转换：differences →different）

转述3   The four countries have their unique education and legal systems as well as traditions.（释义：根据主题句后面扩展句的含义，补充信息，以使主题句意思完整清晰）

Topic sentence 5  Many ordinary jobs may look plain， but they are necessary to society.

转述1   Lots of plain and ordinary jobs are essential to society.（同义替换：necessary→essential）

转述2   Ordinary and plain， lots of jobs are essential to society.（釋义）

值得注意的是，主题句转述的前提是忠实于原文。选择什么样的方法来转述主题句，要根据具体内容确定。适当时候还需要对主题句的信息进行补充，使意思完整清楚。

英语说明文概要写作可以借助说明文的篇章结构特点与段落展开方式定位与提炼主题句，从词、句、语法以及释义的角度转述主题句，从而个性化地表达主旨。但提炼、转化后的主题句还需有机衔接，以确保说明文概要行文流畅，意思完整。

参考文献：

[1]杜龙芳. 英语文章段落内部结构研究[M]//成都翻译协会，等.外语教育与翻译发展创新研究.成都：四川师范大学电子出版社，2016：39.

[2 ]黄苇. 基于原型范畴理论的英语说明文语篇特征研究[J]. 英语教师，2019（21）：50.